Nowadays, the cellular networking is the commonest networking mode in the wireless communication. FIG. 1 is a topology structure of a cellular network constructed by three-sector base stations. Since the network topology structure looks like a honeycomb, it is called as cellular network. As shown in FIG. 1, the circles 1 represent the locations of the three-sector base stations, the arrowheads 2 show the orientation of each of the sectors, and each hexagonal cellular unit 3 in the cellular network denotes the coverage range, known as cell, of the transceiver of one base station. In the coverage area of the cell, a terminal can establish a wireless communication link with the base station. Multiple transceivers form a network to continually cover an area so as to provide user terminals with a seamless wireless communication service.
FIG. 2 is the flow of the traditional network planning. As shown in FIG. 2, the wireless network planning is begun with the user requirements 202, including the designed capacity, coverage range and coverage rate, network performance KPI index. When the designed requirement is clear, it comes to the requirement analysis 204 of the wireless network design, including the prediction of the coverage radius of the coverage area and the analysis of the distribution of the user capacity. The capacity distribution of the coverage area means to determine the equipment configuration and the size of the coverage radius of the cell according to the potential of the user development in the network coverage area. The original design 206 of the network topology structure is completed on the map by combining the two factors, i.e., the network coverage and the user distribution.
Based on the original design of the network topology structure, the process of selecting the appropriate base station sites in the actual coverage environment is called site survey 208. During the site survey, the engineering survey may be performed at the same time to discuss with the owners about the matters concerned such as site rental. Due to various factors, the practically available sites are not necessarily identical with the designed sites. But after the site survey, it is basically ascertained which sites possess the essential conditions for establishing the base stations. Therefore, after the sites are selected, it is necessary to use the network simulation 210 to verify whether the network design requirement is satisfied 212. If the design requirement is satisfied, the network design is output and it comes to the network engineering construction stage 214; otherwise, adjust the site parameters on the simulation platform to find the appropriate site places, antenna heights, and etc., and return to the sites to survey more appropriate sites. The wireless signal propagation model used by the network simulation can be the standard statistic model in the industry, and the corrected model can also be used.
Based on the wireless signal propagation model, the typical propagation model for the traditional cell coverage prediction includes Hata, Cost231 and etc. In order to improve the accuracy of the cell coverage prediction, the propagation model is usually needed to be corrected for typical topographic and geomorphologic environment.
The model correction can be performed at any place before step 210 as shown in the flow of FIG. 2, and its working procedure is as shown in FIG. 3:
Step 302, selecting 3-5 typical areas in a certain urban environment, and choosing typical sites. One or more typical sites can be selected.
Step 304, erecting the continuous wave transmitter at a typical site height for transmission at a fixed power. The vehicular continuous wave receiver moves in the typical area to measure the receiving field strength.
Step 306, collecting sufficient testing data (the data of multiple testing sites with similar topography and geomorphology may be merged, the quantity of one-time testing data may also be increased for the area, and etc.).
Step 308, performing a preprocess for the testing data, including averaging the testing data on the repeated route, eliminating the data too near to or too far from the testing site, merging the testing data of multiple testing sites in the typical areas of a single type, and etc.
Step 310, modifying the parameters of the propagation model using the model correction tool, so as to make its predicted coverage even closer to the actual wireless propagation model of the typical coverage area of this type.
Step 312, forming a model database for the wireless propagation models of several typical areas for the usage of the wireless network simulation.
The traditional method of the propagation model correction corrects the wireless propagation model by collecting sufficient field strength testing data through selecting the typical sites with respect to the typical topography and geomorphology (multiple testing sites are usually needed to be selected such that the testing data covers various topography, geomorphology and site heights).
For the sake of improving the model accuracy, the more the testing sites are selected, the more sufficient the testing data is collected, the better the model correction effect is (multiple parameters in the model are corrected and the parameters corresponding to various geomorphology are corrected).
When testing the wireless signal field strength, transmission apparatus need to be installed in sequence at each testing site in the testing area, and the receiving field strength of the wireless signal is tested for the coverage area of each site in sequence. If n sites are to be tested, the apparatus installation and the testing need to be performed n times, which results in quite large workload.